This book systematically analyzes the measurement validity and reliability of the standardized diversity scores used to quantify age, ethnic, and gender heterogeneity in organizations. It offers human resources practitioners and researchers in the nonprofit, private, and public sectors a hands-on guide on how to assess the measurement reliability and the construct and measurement validity of standardized diversity scores. Examples of measurement validity and reliability assessments are provided throughout the book; more specifically, this book illustrates the use of correlation and factor analyses to assess the validity and reliability of standardized diversity scores.